The present invention relates to medical devices. More specifically the present invention relates to catheters and stylets used to steer the distal tips of catheters.
During some medical procedures, it is necessary for a surgeon to insert a device into a patient through a passage within the patient. Because the passages often bend and turn as they extend through the patient, it is often necessary to guide or otherwise steer the device through the passage to avoid damaging the passages or to position the device in a desired location in the passage.
The implantation of a pacemaker is one example of such a medical procedure. For example, during the implantation of a pacemaker, a cardiologist guides a pacemaker lead through veins into a patient""s heart. Once the pacemaker lead is guided into the patient""s heart, the cardiologist guides the pacemaker lead within the chambers of the heart to a specific location where the pacemaker lead is attached to one of the muscular walls of the heart.
According to the present invention, a medical device is provided that is configured to be inserted into a passage of a patient. The medical device includes a catheter formed to include a lumen therein and a stylet. The stylet includes a tubular member made of a shape-memory material configured to alter a physical characteristic of the catheter in response to activation of the shape-memory material.
According to another embodiment of the present invention, a device is provided that includes a flexible, elongated tubular member having a central axis extending therethrough and a stylet. The stylet includes a shape-memory tube made of shape-memory material and formed to include a lumen extending therethrough. The shape-memory tube is positioned in the tubular member to permit movement of the shape-memory tube relative to the tubular member along the central axis.
According to another embodiment of the present invention, a device is provided that includes a tubular member having a lumen formed therein and a shape-memory member having a lumen formed therein. The shape-memory member is removably received in the lumen of the tubular member. The shape-memory member is movable in response to a change in temperature of the shape-memory member. The shape of the tubular member changes upon movement between the first and second positions.
According to another embodiment of the present invention, a device is provided that is configured to be inserted into a passage of a patient. The apparatus includes a flexible, elongated member having a distal end configured to be inserted into a passage of a patient. The flexible, elongated member includes a primary member, a secondary member, and means for coupling the primary member to the secondary member. The primary member includes a lumen formed therein and is made of a shape-memory material.
According to the present invention, a method for steering a catheter is provided. The method includes the steps of inserting a temperature activated shape-memory tube into a lumen of a catheter; activating the shape-memory tube by changing the temperature of the shape-memory tube from a first temperature to a second temperature different than the first temperature; and removing the shape-memory tube from the catheter.